In a week old qx-70 with only 448 total miles, while stopped at a traffic light, i leaned forward slightly and left side (floor anchor side) of driver's side seatbelt failed by the hip webbing separating from the floor attachment point. this is not the right side attachment that is supposed to be detachable, but the left floor anchor side. had this occurred in an impact i would have been injured. this attachment point is of a strange and illogical design in that it has a probe similar to the regular entry/exit seat belt attachment. either in installation or manufacture this floor attachment device was either not installed correctly or is of a poor design. i am a retired military aircraft accident investigator, safety officer, industrial safety manager, certified safety professional, occupational health and safety technician and an osha authorized outreach instructor as well as a safety engineer. i am very concerned about the potential of injury and/or death with others if this seat belt attachment problem is common. it is my understanding that infiniti and nissan uses this same design. the dealer has been excellent in immediately starting an in-company investigation, but i very concerned about this failure. i have photographs available for email. *tr